Trimming or cutting mechanism for sewing machines



R. M. SHARAF TRIMMING OR CUTTING MEGHANISM FOR SEWING MACHINES Filed April 2 1917 Patented Aug. 28, v1923.

UNITED STfAii.sv

RALPH M. SHARAF, or Naw YORK, N. Y., ASSIGNOR To IaM PATE "fr or BOSTON, MASSACHUSETTS, A' conronnTIoN' -or MASSACHUSETTS.

TRIMMING on CUTTING MEOHANISM Fon SEWING IvIacIIINES. Y

Application ined Api-u2, 1917. serial No. 159,059.Y

To all whom it may concern:

- Beit known that I, RALPH M ,.SHARAF, a ycitizenof the United States, and a resident of the borough of the Bronx, inthe certain new and useful Improvements in Trimming or Cutting Mechanism for SeW- ,ing Machines, of whichv'the following is Y a specification. f

-' an Object of the invention being to'provide means in advanceV of the feeding and sewing elements for cutting outastrip Vof cloth, lace or otherV auxiliary fabric being sewn into the cut out portion. Ag further object is to provide such means which will be operated by the feeding mechanism to the end that an accurate'v and properly timedcutting takes place. Y It is also anv object to provide suchY cutting means which by reason of their Simplicity of construction and attachment, may e readily'removed and sharpened without the necessity of putting the machine out of operation for any material length ofetime, and without requiring the services of an expert.

It is Valso proposed to -provide in connection with the cutting-means, andY edge trimming device by means Ofwhich a novel method of connecting the auxiliary fabric to the main fabric may be carried out, and as a result of which, a secure, neater vand more desirableproduct may be obtainedthan is possible by the methods at present in use.

With these and other objects in. view, an

' embodiment of my invention is shown in theV accompanying drawings, which invention will be hereinafter more fully pointed out in the claims.

In the accompanying drawings;

Figure l is a side elevation vof the presser foot and cutting means, partially .broken away,

Figure 2 is an endY view ,thereof,

Figure 3 is a plan view of thesame,

Figure 4 is a perspective viewof the knife support, and'knives detached the machine, Y 'l Figure 5 is a diagrammatic view of the cutting knife, folding guideA and needle at one side of the presser foot, and illustrating parte, and city and State'of *New York, have invented i i from the improved method of ,sewingpermitted,V

thereby,` h Figure 6 is Y Figure 7 Y. illustrates the resulting stitch and connection of the material. l

Similar referencev characters indicatecorresponding parts throughout the several figures of the drawings. y

Referring. to the drawings, thel sewing machine head (not shown) is provided with` a presser foot bar ll, a needle bari?, of the usual construction, Vand a lace feeding bar i 1l l Siegener MACHINE co.,-

a perspective view ofthe'same l maar 1.3. The presser-footbarll may be raised in the usual manner to permit of the lpreliminary insertion of the cloth intothe same,

by means oft-he manual lifting lever.

-The lace feeding bar-reciprocatespreferably bymeans of the ymechanism' such as that disclosed in my co-pending application Serial NO.159,057, filed simultaneously herewith, or 4inV my application Serial"` No.

127,322,1i1ed'0ct0ber 24, 191e lThe presser :foot comprises'a solid foot portion 16 secured in the bifurcated end 17j of the barll by a screwlS and extends relatively close to the` needles 19. Side `plates 2Ol and 21'aresecured at eachside 'of the.

foot portion by dowels 22 4 and:sc1"cws23, extending at each side ofthe needles and supportingbetween the sameat/the other side of the needle bar ,12, a lace guide 25, and a lace keeper 24' secu'rechby `screws 25 and 26a, the inner curvedfa'cefof the l'lace Y guide block 25 being spaced backI from theA inner edges 4of the side plates 2O and 2l,-so as to form retaining walls to displacement of the lace.

prevent lateraly The lace 'guide' block 25 is provided at its" outer' sidewith a pair ofV spaced slots or guideways,2 6c and 26,'the direction ofthe slots and the outer wall of rthe block being"V drawn from a radius with a point 27 vof the presser foot `bar as a center, and atthat point is pivotally secureda :pivoted knife support.V

This support comprises an arcuatearm 28 lr-Shaped in .cross section and provided yat its linner'feud with a bearing 29 which en` gages a stud 30 securedto lthe presser foot bar, At' its other end there isprovidedV a supporting block 3l extendingat an angle from the VYarm' and. having slots .32 andA 33 therein-in'circular alignment with the slots 26c` and 26d of the lace guide block.v` pair of elongatedblades 3er-'and 35 are Secured in the said 'slots 32'and 33 by a removable plate 36 and a screw 37; these" blades Ae-X- tending downward through the slotsY 26C and 26d andbeing provided at'their lower vends withV inclined knife edges 38fadapted vto be brought above and below the throat plate of thermachine as the knife support is oscillated in a manner to cut out a strip ot cloth prior toV the sewing or" the laceto the-cloth. A cover plate 39 is secured to i the back of the block 2li-to close the slots V26 and 26d and',V extend slightly over ,theV Vsupport block 31 so asto guide the same in its movement. Y

in' ordert'o bring' about the oscillation of the knife support,l provide. a lever LiOslotted at 'its ends 41 and L12 pivoted upon a stub'shaft 113 secured Vto thefplates 20 and'Ql,

thelever beingexterior of the plate E20. The

VYend 41 engages a pin el provided upon the lace feedinioj bar 13 `while the o-ther end en- .e Y gages a Yping/l5 mounted oetween the pair ot 1 lugs 4G and 17 'provided on the endV oi" 'the arm 28. Thus ity will beseen that the'downward movement of the lace feedingbar Ycauses the lcniiel bladesf'to be raisedout oi 'engagement with the cloth, as clearly illustrated-indot vand dash-lines (Fig. '1)' permitting the feeding oi the cloth and lace to take place unhai'npered. At the `end of the f feeding operation and upon' raisingofthe lace feeding bar, the blades are disposed as shown in fulllines in Figure 1, thereby cut-` ting" outthe strip of cloth.V The curved and `inclined cutting edges, togetherwith the movement 'of vthe blades in a circular arc Vresults/in a clean' vand positive cutting'o'f the'materiah the strip of material cut being narrower thanthe lace.

The knives may be accurately adjusted or reinove'dwhen vdesired i'or replacing orsharpening simply removingthe plate 3G by means of the screw 37. The operation is positive and Vexactly timed with the movement of the feeding. mechanism. i

The lace or other auxiliary material to be` secured to the' edges 'of the material from- VVwhich the strip is cut, ,ted-f along;V the block 25 beneath the keeper spring 241 yby means of the Vserrated blade 133.01` thereciprocating lace feeding bar13, the end'oi the blade engaging the lace in its 4upper position at a ldistance above the lower extremity of the block corresponding,r to the amount of lace to be fed for each sewing operation, the down movement of rthe bar 13 moving the blade tothe lower extremity of the.

block.. The keeper 24 prevents any picking up of the lace upon the upward movement ot the feeding' bar. The Vother material is pret erably fed by a plurality of'independently movable dogs, this mechanism and the lace" feedingmechanism beingY preferably of the type disclosed in my col-pending applicaeration, and the lace 52 is fed lthereon, Yas

elearlyshown in FigurelG, so that its selvedfe'53 overlaos the cut edo'es' of the cloth.

g l n A cloth folding guide is arranged beev tween the cutting blades adjacent the needle and progects downwardly 1n a vertical plane ona transverse line between the points, the

blade acts on Athe f cloth at the stitching point. 'This guide' bearsagainst the raw of the cloth lirst previously formed by the cutting device, and'i'olds the samey downwardly through about degrees, as illus! trated `at 55, thereby holding this edge out.- side ot the-point or the needle, while itis maliingjits downjstrcke indicated in dotted lines 5) 1n its zigzag movement the needle recipi'f'ocatesto 'and fro from points just inside o f the vouter line ot' the :folded under edge oi the cloth, to points inside ol? the line on which the cloth has been folded,

see'Fig. 7.` 'Thelower vthread whichris looped bythe thread 57 of the needle by means 'of the vshuttle hookv 5S, isldrawn upi tightly upon the 'up'strjoke` of the needle, completing' Vthe foldingv of the cloth up against thebody or the cloth where it occupies a .position beneath the selvedfgge of the lace. The thread from this shuttle terms the stitch with the thread ofV thel needle in both of its positions, as: for instance, by oscillating` the shuttle` or looper.'.synchrorrVV ously with. the needle, shown in my ap.- plicationA No. 159,053V filed April; 2, 19,17. The over-whipping of the thread in amanner tocompletelyl enclose the fold of the cloth without piercingl of the cloth `at the iolded portion, Aforms a neat, strongl and finished seam. As the edge lofthe lace is not pierced, the needle in both positions en-l tering the body v'ot-the cloth in onel case, and the body of thelace in the other case, there can be no tearingor rav'elin'g of the fabric. In other words, the superposed selvedg'e of the lace and .folded .runder portionv of the` cloth is' completely embraced-by the stitching, but they are not pierced by the needles, the loops -at each side being spaced from the free or outer edge of the "fold of the. cloth, and from they line. on which the clothV is folded.V The appearance of this method of sewing is clearly illustrated diagrammatically in Figure 6, in which the lace is considered as transparent,'and the lace guide is not shown. It will of course be understood that this action of the zigzag stitching is applicable to the sewing of the lace or other auxiliary fabric with the use of one needle only.

I have illustrated and described a preferred and satisfactory embodiment of my invention, but it is obvious that changes may be made therein Within the spirit and scope thereof as defined in the appended claims.

I claim:

l. In a sewing machine, a presser foot provided with a circularly curved guideway lying in a vertical plane, a'trimmer knife movable along said guideway, and an arm carrying said knife and pivoted to swing about a horizontal axis passing through the center from which said guideway is curved.

2. In a sewing machine, a guide curved according to the arc of a circle, a knife movable along said guide, and an arm carrying said knife and pivoted to swing about an axis passing through the center of said circle.

3. In a sewing machine, a guide curved according to the arc of a circle, a knife of like curvature movable along said guide, and an arm carrying said knife and pivoted to swing about an axis passing through the center of said circle.

4. In a sewing' machine,'a member having a guide slot curved according to the arc of a circle, an arm pivoted` to swing about an axis passing through the center of said circle, a holder on said arm, provided with `a slot of the same curvature as said guide slot and in alignment therewith, and a knife carried by said holder and adjustable in the slot thereof, and extending into said guide slot.

5. In a sewing machine, a presser foot provided with an upright circularly-curved guideway, a trimmer knife movable along said guideway, and an arm carrying saidknife and p-ivoted to swing about an axis perpendicular to the plane of said guideway and passing through the center from which said guideway is curved.

6. A trimming or cutting mechanism for sewing machines, comprising a pivoted member, a knife supported by said pivoted member, a feed bar movable up and down and having a feed action on its downstroke and inactive on its upstroke, as regards feeding, and means operatively connecting said feed bar to said knife, to impart downward movement to said knife upon the upward movement of said feed bar.v

7 In a trimming or cutting mechanism for sewing machines, lthe combination of a guide provided with slots curved according to circular arcs and disposed in spaced parallel planes, knives cooperating with said slots, said knives being curved and pivotally supported, the center of curvature of-said knives of said guide slots being the pivotal point of the knives.

8. In a sewing machine, a member having a relatively stationary guide slot curved according to the arc cfa circle, a movable holder provided with a slot of the same curvature as said guide and in alignment therewith, a knife carried by said holder having a corresponding curvature to said slots of said guide and holder and adjustable lengthwise in the slot of said holder and extending int-o said guide slot, and means for moving the knife lengthwise of said guide slot.Y y Y 9. In a sewing machine, a presser vfoot provided with a guideway curved according to the arc of a circle, an arm mounted to swing about the center of said circle, a knife carried by said arm and movable along said guideway, a lever fulcrumed on the presser foot between said guideway and the center of said circle, and in operative engagement with said arm, and a vertically reciprocating feeding member .engaging said'lever on'the side of its fulcrum opposite to the one where it engages said arm.

l0. In a sewing machine, the combination with a lace feeding means, a guide curved according to the arc of a circle adjacent the lace feeding means,a curved knife movable along said guide, and means operated by the lace feeding means for moving the knife in saidA guide.

1l. In a sewing machine, the combination with a lace feeding means, comprising a lace guiding means, feeding means therefor, a curved guide adjacent'the lace guiding means and arranged in the arc of a circle, a curved knife movable along said guide, and means operated by the lace feedmg means for moving the knife in said guide. Y

12. In a sewing machine, the combination with a lace guiding vand feeding means, comprising a curved guide adjacent the lace guiding means and arranged in the arc of a circle, a curved knife movable along said guide, and means operated by the lace feeding means for operating the'knifein said guide and moving it out of cutting position during the feeding of the lace.

In testimony, that I claim the foregoingV as my invention, I have signed my name in presence of two subscribing witnesses.`

RALPH M. SHARAF. Witnesses:

D. LEWIS MATTERN, Mon M. WEINBERG. 

